[Preparation and identification of the polyclonal antibody against human VSTM1].

AIM: To prepare and characterize the polyclonal antibody against human VSTM1. METHODS: VSTM1 has two main isoforms, VSTM1-v1, a type I transmembrane protein, and VSTM1-v2, a classical secretory protein, lacking only the transmembrane domain compared with VSTM1-v1. Two recombinant prokaryotic proteins of VSTM1-v2, Trx-His-S-VSTM1-v2 and GST-VSTM1-v2, were constructed, expressed, purified, and then used for immunization of New Zealand rabbits to prepare anti-VSTM1 antibody and coupling with CNBr-activated Sepharose 4B to purify the antibody by immunoaffinity chromatography, respectively. ELISA was performed to detect the titers of the antiserums. After purification, the antibody was identified by Western blotting and immunofluorescence cytochemistry. RESULTS: The titers of the antiserums from the two immunized rabbits were both 1:10(6);. Western blotting confirmed that the purified antibody could recognize both the overexpressed and endogenous VSTM1 specifically. Immunofluorescence cytochemistry verified that the antibody could also recognize the overexpressed VSTM1-v1 on the surface of HEK293T cells. CONCLUSION: The rabbit antibody against human VSTM1 of a high titer has been obtained, which can be used for recognizing endogenous VSTM1 in immunofluorescence cytochemistry.

[Sensitizing effect of recombinant human PDCD5 protein on chemotherapy of acute monocytic leukemia cell line U937 and its mechanism].

This study was aimed to investigate the sensitizing effect of recombinant human PDCD5 (rhPDCD5) protein on chemotherapy of U937 cell line and its mechanism. The flow cytometry was performed to assess the changes of cell apoptosis and cell cycle influenced by rhPDCD5. Hochst 33258 staining was used to observe morphology of the apoptotic cells. The activity change of caspase-3 was detected to analyse the possible mechanisms of rhPDCD5-induced apoptosis. RT-PCR was performed to observe the expression level of drug-resistant genes. The results showed that the percentage of apoptotic cells and the activity of caspase-3 remarkably increased in U937 cells treated with rhPDCD5 combined with chemotherapeutic drug; the cell cycle arrest induced by anti-tumor drug was also enhanced when combined with rhPDCD5; meanwhile, the expression levels of drug-resistant genes were down-regulated in jointly treated U937 cells. It is concluded that the chemosensitizing mechanisms of rhPDCD5 are complex. rhPDCD5 may increase the cytotoxicity of anti-tumor drugs by promoting the caspase-3-related apoptosis, influencing cell cycle, decreasing the expression of drug-resistant genes and reversing drug-resistance.

[Both PIK3IP1 and its novel found splicing isoform, PIK3IP1-v1, are located on cell membrane and induce cell apoptosis].

OBJECTIVE: To find novel isoform of PIK3IP1 and analyze their effects on cell viability, subcellular localization, and expression profile in cell lines. METHODS: RT-PCR was used to clone PIK3IP1 and its novel splicing isoform PIK3IP1-v1 from multi-tissue cDNA pool. By cell-based assays, we studied how PIK3IP1 and PIK3IP1-v1 affected the activity of Renila luciferase and morphological change in the HEK 293T cells. Furthermore, flow cytometry experiment was used to validate that overexpression of both splicing isoforms could induce cell apoptosis. Bioinformatics analysis was used to identify structural characteristics of these two splicing isoforms. By fluorescence microscopy assay, we identified their subcellular localization. RT-PCR was used to detect the expression of PIK3IP1 in the cell lines. RESULTS: PIK3IP1 and its novel splicing isoform PIK3IP1-v1 were cloned and constructed into the pcDNA-and pEGFP-expression plasmids. They both had signal peptide and transmembrane domain. Nevertheless, PIK3IP1-v1 was in absence of an extracellular Kringle domain. They could inhibit the activity of Renila luciferase and induce cell apoptosis. Simultaneously, both splicing isoforms are validated with subcellular localization on cell membrane and lowly expressed in many cell lines. CONCLUSION: PIK3IP1-v1 is a novel splicing isoform of PIK3IP1. Both of them are located on cell membrane and can induce cell apoptosis.

[Preparation, purification and characterization of the polyclonal antibody against human CMTM4].

AIM: To prepare, purify and characterize the polyclonal antibodies against CMTM4. METHODS: Four polypeptides named peptide 1, 2, 3, and 4 were synthesized based on the bioinformatics analysis of the three isoforms of CMTM4, CMTM4-v1, -v2, and -v3, and coupled with keyhole limpet hemocyanin (KLH) for immunization. Among them, peptide 1, 2, and 3, common for CMTM4-v1, v2, and v3, were mixed for immunization to prepare the antibody which can recognize all of the three isoforms (Ab1); while peptide 4, which is specific for CMTM4-v1, was injected separately into New Zealand rabbits to prepare the antibody specifically targeting CMTM4-v1 (Ab2). ELISA assay was used to detect the titers of the antibodies. After purification by immunoaffinity chromatography, Ab1 and Ab2 were identified by Western blot and immunohistochemistry assays. RESULTS: The titers of Ab1 and Ab2 were 1:10(5) and 1:10(6), respectively. Western blot confirmed their high specificity. Ab1 could also be used for immunohistochemistry analysis, but Ab2 could not. Immunohistochemistry analysis with Ab1 demonstrated the high expression level of CMTM4 in human testis, which was consistent with the previous result of Northern blot. Moreover, Western blot and immunohistochemistry analysis verified that Ab1 can also recognize mouse Cmtm4. CONCLUSION: Two specific antibodies against human CMTM4 were obtained, which will be helpful for further study.

[Application of NF-kappaB reporter and Dual-Luciferase assays in the measure of bioactivity of interleukin-1beta and interleukin-1 receptor antagonist].

OBJECTIVE: To develop a reporter gene system based on transient transfections with a NF-kappaB responsive reporter gene to detect the bioactivity of IL-1beta and IL-1 receptor antagonist. METHODS: NF-kappaB reporter and Dual-Luciferase assays were applied to measure the bioactivity of IL-1beta and IL-1 receptor antagonist in mouse EL4 cells (some subclones of EL4 cells expressed high level of IL-1 receptor on cell surface). pNF-kappaB-luc and pRL-TK, used as an internal control, were co-transfected into EL4 cells and then the IL-1beta was added. RESULTS: The results indicated that IL-1beta was able to induce the expression of this luciferase, which could be blocked by IL-1 receptor antagonist. The optimal dose of IL-1beta was 5 microg/L in Dual-Luciferase assay, whose bioactivity can be effectively inhibited by IL-1ra at 50 microg/L. CONCLUSION: We have established a new method to detect the bioactivity of IL-1beta and IL-1 receptor antagonist, which can give repeatable results.

[Preparation and identification of monoclonal antibodies against SARS-CoV putative protein X4].

OBJECTIVE: To obtain monoclonal antibodies against putative protein X4 of SARS-CoV for further study of the structure and function of protein X4. METHODS: Balb/c mice were immunized with recombinant Protein X4, hybridoma cell lines secreting monoclonal antibodies against protein X4 were screened by regular cell fusion and subcloning approach. The specificities of these monoclonal antibodies were determined by Western blotting and Immunofluorescence assay. RESULTS: Three hybridoma cell lines (8A5, 8H6 and 4A2) stable in secreting specific monoclonal antibodies were successfully obtained. They could bind specifically to protein X4 proved by Western blotting. All of them belonged to the IgG2a isotype proved by antigen mediated ELISA. Indirect Immunofluorescence assay indicated that they could specifically bind to protein X4 expressed in SARS-CoV infected Vero E6 cells. CONCLUSION: Monoclonal antibodies of high specificity against protein X4 have been successfully prepared, which laid the foundation for the further study of protein X4.

The protein X4 of severe acute respiratory syndrome-associated coronavirus is expressed on both virus-infected cells and lung tissue of severe acute respiratory syndrome patients and inhibits growth of Balb/c 3T3 cell line.

BACKGROUND: The genome of the severe acute respiratory syndrome-associated coronavirus (SARS-CoV) includes sequences encoding the putative protein X4 (ORF8, ORF7a), consisting of 122 amino acids. The deduced sequence contains a probable cleaved signal peptide sequence and a C-terminal transmembrane helix, indicating that protein X4 is likely to be a type I membrane protein. This study was conducted to demonstrate whether the protein X4 was expressed and its essential function in the process of SARS-CoV infection. METHODS: The prokaryotic and eukaryotic protein X4-expressing plasmids were constructed. Recombinant soluble protein X4 was purified from E. coli using ion exchange chromatography, and the preparation was injected into chicken for rising specific polyclonal antibodies. The expression of protein X4 in SARS-CoV-infected Vero E6 cells and lung tissues from patients with SARS was performed using immunofluorescence assay and immunohistochemistry technique. The preliminary function of protein X4 was evaluated by treatment with and over-expression of protein X4 in cell lines. Western blot was employed to evaluate the expression of protein X4 in SARS-CoV particles. RESULTS: We expressed and purified soluble recombinant protein X4 from E.coli, and generated specific antibodies against protein X4. Western blot proved that the protein X4 was not assembled in the SARS-CoV particles. Indirect immunofluorescence assays revealed that the expression of protein X4 was detected at 8 hours after infection in SARS-CoV-infected Vero E6 cells. It was also detected in the lung tissues from patients with SARS. Treatment with and overexpression of protein X4 inhibited the growth of Balb/c 3T3 cells as determined by cell counting and MTT assays. CONCLUSION: The results provide the evidence of protein X4 expression following SARS-CoV infection, and may facilitate further investigation of the immunopathological mechanism of SARS.

[Preparation, identification, and analysis on tissue chips of polyclonal anti-peptide antibody to chemokine-like factor 1].

OBJECTIVE: To prepare the polyclonal anti-peptide antibody against chemokine-like factor1 (CKLF1) and apply it to the expression and functional studies of CKLF1. METHODS: CKLF1 was analyzed with bioinformatics methods. The 16 amino acids sequence peptide was selected from CKLF1 C terminal end. Antibody was raised by immunizing rabbits with the peptide conjugated to keyhole limpet hemocyanin (KLH). RESULTS: A high titer polycolonal antibody was obtained from the rabbit against the peptide. ELISA analysis proved that the titer of rabbit serum against anti-peptide of CKLF1 was up to 10(-4). Western blot analysis revealed that it could react not only with recombinant CKLF1 expressed in a cell-Free Protein Biosynthesis System and Drosophila S2 cells, but also recognize the endogenous CKLFs in the tissue array. Positive staining was detected in the normal bronchial cartilage, gastric mucosa, and gastric smooth muscle tissues. Normal rectum and well-differentiated rectal carcinoma showed strong positive staining, but the poor-differentiated rectal carcinoma samples revealed negative staining. CONCLUSION: The anti-peptide antibody can specifically recognize CKLFs and may be a useful reagent for the detection of CKLF1.

[Study on the metabolism of cartilage matrix by the chondrocytes in osteoarthritic condylar cartilage].

OBJECTIVE: To study the characteristics of cellular metabolism of mandibular condylar chondrocytes in repairing state of osteoarthrosis and investigate its role in the pathogenesis of the disease. METHODS: Temporomandibular joint osteoarthrosis model of rabbits was created by the partial resection of joint disc and confirmed with histological diagnosis. The chondrocytes were harvested from osteoarthritic condylar cartilage in the repairing state and cultured in vitro under the monolayer culture condition. The cellular expression of cartilaginous matrix protein, collagenase and growth factors between the osteoarthritic chondrocytes and the normal controls were measured with RT-PCR technique to outline the basic feature of the osteoarthritic cells. RESULTS: The cultured cells were confirmed as chondrocytes with their ability of expression of collagen type II and Aggrecan. In the reactive repairing state of osteoarthrosis, the chondrocytes showed the imbalance of expression of ECM proteins, and increased expression of collagenase and endogenous growth factors such as IGF-1 and TGF-beta1. CONCLUSIONS: This study found the active anabolism of the chondrocytes within the osteoarthritic condylar cartilage and the imbalance synthesis of cartilage matrix. These repairing attempts by the osteoarthritic chondrocytes may be impossible to restore the primary homeostasis within the condylar cartilage.

Chemokine-like factor 1, a novel cytokine, contributes to airway damage, remodeling and pulmonary fibrosis.

BACKGROUND: Chemokine-like factor 1 (CKLF1) was recently identified as a novel cytokine. The full-length CKLF1 cDNA contains 530 bp encoding 99 amino acid residues with a CC motif similar to that of other CC family chemokines. Recombinant CKLF1 exhibits chemotactic activity on leucocytes and stimulates proliferation of murine skeletal muscle cells. We questioned whether CKLF1 could be involved in the pathogenesis of inflammation and proliferation in the lung. Therefore we used efficient in vivo gene delivery method to investigate the biological effect of CKLF1 in the murine lung. METHODS: CKLF1-expressing plasmid, pCDI-CKLF1, was constructed and injected into the skeletal muscles followed by electroporation. Lung tissues were obtained at the end of week 1, 2, 3 and 4 respectively after injection. The pathological changes in the lungs were observed by light microscope. RESULTS: A single intramuscular injection of CKLF1 plasmid DNA into BALB/c mice caused dramatic pathological changes in the lungs of treated mice. These changes included peribronchial leukocyte infiltration, epithelial shedding, collagen deposition, proliferation of bronchial smooth muscle cells and fibrosis of the lung. CONCLUSIONS: The sustained morphological abnormalities of the bronchial and bronchiolar wall, the acute pneumonitis and interstitial pulmonary fibrosis induced by CKLF1 were similar to phenomena observed in chronic persistent asthma, acute respiratory distress syndrome and severe acute respiratory syndrome. These data suggest that CKLF1 may play an important role in the pathogenesis of these important diseases and the study also implies that gene electro-transfer in vivo could serve as a valuable approach for evaluating the function of a novel gene in animals.

[The protective effect of interleukin-1 receptor antagonist on postischemic reperfused myocardium and its possible mechanism].

OBJECTIVE: To observe the dynamic changes of plasma inflammatory cytokine interleukin-1 beta (IL-1 beta) in patients with acute myocardiac infarction (AMI) before and after recanalization of the infarct related artery (IRA) and to observe the effect of recombinant human IL-1 receptor antagonist (rhIL-1ra) on the postischemic reperfused myocardium in experimental rabbits. METHODS: (1) ELISA was used to measure the plasma IL-1 beta of 22 AMI patients, 20 males and 2 females, aged 64 +/- 12, before emergency percutaneous coronary intervention (PCI), and 12 hours and 24 hours after-intervention, and measure the plasma IL-1 beta of 8 healthy controls, 6 males and 2 females, aged 56 +/- 9. (2) Forty rabbits underwent ligation of the left circumflex branch of coronary artery (LCX) for 50 minutes and reperfusion for 4 hours after the ligatures were untied. The rabbits were randomly divided into 4 groups of 10 rabbits to be injected into the left ventricle immediately before the reperfusion with rhIL-1ra 10 mg/kg (group A), 20 mg/kg (group B), or 40 mg/kg (group C), and normal saline (control group) respectively. After reperfusion of 4 hours, the LCX was re-ligated. Evans blue was injected into the left ventricle. 15% KCl was injected intravenously to kill the rabbits. Their hearts were taken out to weigh the non-ischemic, ischemic, and necrotic cardiac muscles so as to calculate the infarct size. The myoperoxidase (MPO) activity was measured by colorimetry. Sections of myocardium were made. The number of apoptotic cardiomyocytes was evaluated by TUNEL method. The apoptotic rate of cardiomyocyte was measured by annexin V method. The DNA expression of myocardium was detected by DNA laddering method. The expressions of Bcl-2 and Bax apoptosis genes were assessed. RESULTS: (1) The average plasma IL-1 beta level of the 22 AMI patients before emergency PCI was significantly higher than that of the controls (28 pg/ml +/- 9 pg/ml vs. 20 pg/ml +/- 11 pg/ml, P < 0.05), and became the highest 12 hours after the intervention (86 pg/ml +/- 14 pg/ml), and the high level lasted to 24 hours after emergency PCI. (2) In the ischemia-reperfusion rabbit model, the infarct size was 47% +/- 7% in the group A, 34% +/- 8% in the group B, 31% +/- 6% in the group C, and 61% +/- 11% in the control group (P < 0.05, 0.01, and 0.01 respectively). The activity of myocardial MPO was 16.6 +/- 3.6 min(-1).g.w.w(-1) in the group A, 10.9 min(-1).g.w.w(-1) +/- 1.9 min(-1).g.w.w(-1) in the group B, 7.8 min(-1).g.w.w(-1) +/- 2.2 min(-1).g.w.w(-1) in the group C, and 20.5 min(-1).g.w.w(-1) +/- 4.5 min(-1).g.w.w(-1) in the control group (P < 0.05, 0.01, and 0.01 respectively). The cardiomyocyte apoptosis evaluated by TUNEL was 38.3 n/HP +/- 7.4 n/HP in the group A, 25.6 n/HP +/- 6.8 n/HP in the group B, 12.2 n/HP +/- 3.3 n/HP in the group C, and 44.4 n/HP +/- 9.5 n/HP in the control group (P < 0.05, and P < 0.01 respectively in comparison between the group B and the control group and between the group C and the control group). The apoptotic rate by annexin V method was 11.6% +/- 2.7% in the group A; 7.7% +/- 2.4% in the group B, 4.7% +/- 1.4% in the group C, and 15.6% +/- 3.5% in the control group (P < 0.05, 0.01, and 0.01 respectively). DNA electrophoresis showed scaling ladder pattern only in the control group. The fluorescent density of the apoptosis gene Bax in myocardium was 24.9 +/- 8.2 in the group A; 15.5 +/- 3.4 in the group B, 10.6 +/- 2.5 in the group C, and 33.3 +/- 9.4 in the control group (P = 0.0298, 0091, and 0052 respectively) and no significant difference in the expression of Bcl-2 was shown among the 4 groups. Myocardial MPO was correlated with cardiomyocyte apoptosis (r = 0.86 by TUNEL, P < 0.01; r = 0.75 by Annexin V method, P < 0.05). CONCLUSION: Inflammatory cytokine IL-1 beta is involved in myocardial ischemia-reperfusion injury. With potential therapeutic value in prevention and treatment of ischemia-reperfusion injury to myocardium, rhIL-1ra may reduce myocardial ischemia-reperfusion injury by suppression of cardiomyocytes apoptosis mediated by IL-als; 0.86 by TUNEL, P < 0.01; r = 0.75 by Annexin V method, P < 0.05). CONCLUSION: Inflammatory cytokine IL-1 beta is involved in myocardial ischemia-reperfusion injury. With potential therapeutic value in prevention and treatment of ischemia-reperfusion injury to myocardium, rhIL-1ra may reduce myocardial ischemia-reperfusion injury by suppression of cardiomyocytes apoptosis mediated by IL-1.

Expression of PDCD5, a novel apoptosis related protein, in human osteoarthritic cartilage.

AIM: To investigate the expression features of PDCD5 (programmed cell death 5 protein) in osteoarthritic and normal human cartilage, and speculate on its potential functions in the pathogenesis of osteoarthritis (OA). METHODS: Articular cartilage specimens were obtained from 30 patients with OA and 16 healthy patients at the time of arthroplasty. Expression of PDCD5 was detected by flow cytometry, immunofluorescence, RT-PCR and immunohistochemical analysis. RESULTS: Enhanced expression and nuclear accumulation of PDCD5 in OA chondrocytes were found. PDCD5-positive chondrocytes were mainly distributed in the superficial and deep zones of OA tissue sections, as opposed to, in the superficial and middle regions of normal healthy tissue sections. CONCLUSION: Since apoptotic chondrocyte death occurs more frequently in OA cartilage than in normal healthy cartilage and PDCD5 is an apoptosis-related protein, the different expression patterns of PDCD5 in OA cartilage from that in normal healthy cartilage indicate that PDCD5 is involved in the pathogenesis of OA.

[Regulation of [12Asp]K-ras4B on transcriptional activity of estrogen receptor in endometrial carcinoma HEC-1A cell lines].

OBJECTIVE: To investigate the effect of mutant-type [(12)Asp]K-ras4B gene on the expression of estrogen receptor (ER) alpha and beta and their transcriptional activity as a transcription factor in endometrial carcinoma HEC-1A cell line. METHODS: (1) Effect of [(12)Asp]K-ras4B on the expression of ER alpha and beta were determined using Western blot assay. (2) Eukaryotic expression plasmid pGL3-luciferase-ERE containing luciferase report gene and estrogen receptor element (ERE) was constructed, and co-transfected into NIH3T3 and HEC-1A cell lines with pEGFP-N1 to examine the effect of [(12)Asp]K-ras4B on ER transcription that is regulated by estradiol. In addition, they were transfected into pSV5-HER0 (containing full length wide type ERalpha cDNA) and pCMV-rafS621A (inhibiting raf kinase) plasmids to test the effect of [(12)Asp]K-ras4B/raf signal pathway on transcriptional activity of ER proteins. RESULTS: (1) Protein level of ERs expressed in pcDI transfected control cells was low while it was increased for 3.6-fold (97 +/- 25, 349 +/- 67, P < 0.01) and 1.9-fold (128 +/- 37, 349 +/- 30, P < 0.05) in ERalpha and ERbeta, respectively, in pcDI-[(12)Asp]K-ras4B NIH3T3 cells after transfection. (2) In pcDI-[(12)Asp]K-ras4B NIH3T3 cells, the ratios for ERalpha and and ERbeta levels before transfection of rafS621A plasmids to that after the transfection, were 2.4:1 (724 +/- 45, 310 +/- 46, P < 0.05) and 1.8:1 (493 +/- 20, 284 +/- 20, P < 0.01), respectively; In HEC-1A cells, these ratios were 2.1:1 (566 +/- 22, 279 +/- 30, P < 0.01) and 2.4:1 (405 +/- 33, 165 +/- 15, P < 0.01), respectively. (3) In low serum (2%) culture condition, estradiol (E(2)) stimulated luciferase activity with an increase of 13-fold (130 +/- 42, 1681 +/- 242, P < 0.01) in pcDI-[(12)Asp] K-ras4B NIH3T3 cells, 19-fold (141 +/- 39, 2644 +/- 331, P < 0.001) in HEC-1A cells, respectively, when compared with those in the absence of E(2). (4) In pSV5-HER0 transfected pcDI-[(12)Asp] K-ras4B NIH3T3 cells and HEC-1A cells, compared to the untransfected cells, the ER transcriptional activity in the transfected cells increased markedly. The luciferase activity was increased for 8-fold (1048 +/- 91, 8099 +/- 452, P < 0.01) and 6-fold (2148 +/- 259, 12,705 +/- 2670, P < 0.001), respectively. rafS621A mutant had suppressive effects on luciferase activities in HEC-1A cells and pcDI-[(12)Asp]K-ras4B NIH3T3 cells. The ratio of luciferase activities in pcDI-[(12)Asp]K-ras4B NIH3T3 and HEC-1A cells, before and after transfection was 7.8:1 (1184 +/- 168, 152 +/- 27, P < 0.05) and 6.4:1 (1949 +/- 212, 304 +/- 60, P < 0.01), respectively. CONCLUSIONS: (1) [(12)Asp]K-ras4B can enhance the expression of ERalpha and beta proteins. This may be correlated with [(12)Asp]K-ras4B/raf signaling pathway. (2) The effect of mutant-type [(12)Asp]K-ras4B gene on ERs transcriptional activity in HEC-1A cells appears to need E(2).

Gene transfer of kringle 5 of plasminogen by electroporation inhibits corneal neovascularization.

PURPOSE: To test the efficacy of naked plasmid that expresses human kringle 5 of plasminogen (K5) in suppressing experimental corneal neovascularization in a rat model. METHODS: A eukaryotic expression plasmid encoding human K5 (pSecK5) was constructed. COS cells were transiently transfected with pSecK5 using a lipid-based transfection reagent. K5 secretion was confirmed by Western blot analysis. The effect of the secreted K5 on the proliferation of human umbilical vein endothelial cells (HUVECs) was investigated colorimetrically. Forty-three Sprague-Dawley rats were used for a corneal neovascularization suppression experiment. Corneal injury was induced by placing a disk of filter paper (immersed in 1 mol/l NaOH, 3.0 mm in diameter) on the corneal surface for 2 min. The cornea was immediately washed with saline. pSecK5 and empty plasmids were injected subconjunctivally, and square-wave electric pulses were immediately applied to the eyes. The expression of K5 was analyzed by reverse transcription polymerase chain reaction (RT-PCR) and immunohistochemistry. The extent of corneal neovascularization was evaluated by scores. RESULTS: The constructed plasmid could express itself in COS cells. Conditioned medium from K5-transfected COS cells apparently inhibited HUVEC proliferation, compared with conditioned medium from COS cells transfected with empty plasmid or nontransfected cells. RT-PCR and immunohistochemistry confirmed the expression of K5 in the conjunctiva and cornea. Corneal neovascularization was significantly suppressed by K5 gene transfer in rats' eyes. CONCLUSION: In a rat model, K5 gene transfer by subconjunctival injection and electroporation can effectively inhibit corneal neovascularization induced by an alkali burn.

[Carcinogenesis and its mechanism of mutant-type[12Asp]K-ras4B gene].

BACKGROUND & OBJECTIVES: Ras gene plays an important role in the extra- and intra-cellular signal transduction pathway. It mediates series cascade reactions, and eventually actives transcriptional factors in nucleus. It is unknown on the mechanism of carcinogenesis of Ras gene in endometrial carcinoma, though K-ras mutant is very common in endometrial atypical hyperplasia and carcinoma. On basis of discovering the mutation in 12th codon of K-ras in endometrial carcinoma cell line, HEC-1A, we explored the carcinogenesis and molecular mechanism of mutant-type [12Asp] K-ras4B gene. METHODS: (1) Full-length [12Asp]K-ras4B cDNA was amplified with RT-PCR, then inserted into pcDI eukaryotic expressive vector. (2) Morphological change, growth kinetics in vitro and tumorigencity in nude mice in vivo after-before transfection were observed. (3) To test the cell growth kinetics by methyl thiazolium tetrazolium (MTT) and [3H]thymidine incorporation method. RESULTS: (1) The authors have successfully constructed eukaryotic expression plasmid pcDI-[12Asp] K-ras4B; (2) To confirm that [12Asp] K-ras4B mutant can trigger the neoplastic transformation of NIH3T3 cells by test in vitro and in vivo. (3) After pMCV-RasN17 plasmid, a Ras mutant were transfected into pcDI-[12Asp] K-ras4B cells, the growth of this cell were restrained significantly in comparison with control group. (4) These findings indicate the expression of RafS621A resulted in remarkable inhibition in proliferation of pcDI-[12Asp]K-ras4B cell (P < 0.05). However, RafCAAX mutant can enhance pcDI-[12Asp]K-ras4B cell growth (P < 0.05). CONCLUSIONS: (1) [12Asp]K-ras4B gene alone is able to cause neoplastic transformation in NIH3T3 cells in vitro and in vivo. (2) [12Asp]K-ras4B-induced NIH3T3 cells neoplastic transformation required Raf signaling pathway.

[Molecular cloning, characterization, chromosomal assignment, genomic organization and verification of SFRS12(SRrp508), a novel member of human SR protein superfamily and a human homolog of rat SRrp86].

We have identified and characterized a novel human serine-arginine-rich (SR) splicing regulatory protein 508 (SRrp508) gene that is related to other members of the growing SR superfamily, but only homologous to rat (Rattus norvegicus) serine-arginine-rich splicing regulatory protein 86 (SRrp86) gene. The full-length cDNA of 3811 bp for human SRrp508 was cloned through a blast search of public databases following the identification of a cDNA contig of 658 bp obtained by EST assembly with full robotization in supercomputer in large-scale. Structurally, human SRrp508 encodes a polypeptide of 508 amino acids, which contains a single amino-terminal RNA recognition motif (RRM) and two carboxy-terminal domains rich in serine-arginine dipeptides that are highly conserved among other members of the SR superfamily. The conserved SR and RRM domains emphasize the biological importance of this gene. The SRrp508 gene, which contains 12 exons ranging from 0.096 to 2.093 kb and 11 introns ranging from 0.14 to 5.153 kb, is mapped to the human cytogenetic region 5q11.2-q12.1 using the bioinformatic analysis, and it does not link to any other genes. Furthermore, we have experimentally cloned and sequenced a cDNA fragment of 1680 bp containing the full-length ORF of 1527 bp in this novel human gene by RT-PCR from the single-stranded human pancreas cDNA library (Clontech), which is fully identical with that of the in silico cloning determined by the nucleotide sequencing. Thus, we in silico cloned his gene with GenBank accession number of AF459094 identified solely by bioinformatic analysis of the nucleotide and protein. This novel gene has promotors, TATA-box, several stop codons in the upstream of ORF, and PolyA signal in the downstream of ORF. Based on the above results, it can be concluded that we have obtained a complete novel human gene. The gene sequence exhibits good overall homology to that of rat SRrp86 gene, with 84% and 86% identity over the full-length nucleotide and protein, respectively, and with 96% and 86% identity over the serine-rich domain (RS) or arginine-rich domain (RA), respectively. The full-length sequence exhibits little overall homology to any other known protein at either the nucleotide or the amino acid level. The other two most closely related proteins, with 34% and 35% identity over the full-length protein, respectively, or with 51% and 54% identity over the full-length nucleotide of ORF, respectively, are drosophila serine-arginine-rich protein 54 (SRp54) and human arginine-rich nuclear protein 54 (p54). When comparisons are restricted to the RS or RA domains, the percent identity increased for both SRp54 and p54 are 44% and 54% or 38% and 43%, respectively. These results well demonstrate that only the novel human protein of 508 amino acids cloned is the human homolog of rat SRrp86, thus correcting the standpoint made by Barnard and Patton (Barnard DC, Patton JG. Identification and Characterization of a Novel Serine-Arginine-Rich Splicing Regulatory Protein. Molecular and Cellular Biology, 2000, 20(9): 3049-3057) that human arginine-rich nuclear protein 54 (p54) is the human homolog of the rat SRrp86, and suggesting that human SRrp508 is a new member of this growing superfamily of SR proteins. SRrp508 has an extensive expression profile, and may be a transcriptional factor. On the basis of its sequence and functional properties, we have named this protein SRrp508 for SR-related splicing regulatory protein of 508 amino acids. In summary, by combining bioinformatic analysis with experimental verification, we have successfully cloned the human cDNA homolog of rat SRrp86, which is verified by a series of theoretical and experimental evidence. The HGNC has just given SRrp508 gene entry the nomenclature information containing APPROVED SYMBOL: SFRS12; NAME: splicing factor, arginine/serine-rich 12; and ALIAS: DKFZp564B176, SRrp86. We have cloned this gene for near one year with no person landing the GenBank for registering the same gene. Our newly-established technique line will be helpful in discovering much more novel human genes.